Platelet Transfusion before CVC Placement in Patients with Thrombocytopenia.

BACKGROUND: Transfusion guidelines regarding platelet-count thresholds before the placement of a central venous catheter (CVC) offer conflicting recommendations because of a lack of good-quality evidence. The routine use of ultrasound guidance has decreased CVC-related bleeding complications. METHODS: In a multicenter, randomized, controlled, noninferiority trial, we randomly assigned patients with severe thrombocytopenia (platelet count, 10,000 to 50,000 per cubic millimeter) who were being treated on the hematology ward or in the intensive care unit to receive either one unit of prophylactic platelet transfusion or no platelet transfusion before ultrasound-guided CVC placement. The primary outcome was catheter-related bleeding of grade 2 to 4; a key secondary outcome was grade 3 or 4 bleeding. The noninferiority margin was an upper boundary of the 90% confidence interval of 3.5 for the relative risk. RESULTS: We included 373 episodes of CVC placement involving 338 patients in the per-protocol primary analysis. Catheter-related bleeding of grade 2 to 4 occurred in 9 of 188 patients (4.8%) in the transfusion group and in 22 of 185 patients (11.9%) in the no-transfusion group (relative risk, 2.45; 90% confidence interval [CI], 1.27 to 4.70). Catheter-related bleeding of grade 3 or 4 occurred in 4 of 188 patients (2.1%) in the transfusion group and in 9 of 185 patients (4.9%) in the no-transfusion group (relative risk, 2.43; 95% CI, 0.75 to 7.93). A total of 15 adverse events were observed; of these events, 13 (all grade 3 catheter-related bleeding [4 in the transfusion group and 9 in the no-transfusion group]) were categorized as serious. The net savings of withholding prophylactic platelet transfusion before CVC placement was $410 per catheter placement. CONCLUSIONS: The withholding of prophylactic platelet transfusion before CVC placement in patients with a platelet count of 10,000 to 50,000 per cubic millimeter did not meet the predefined margin for noninferiority and resulted in more CVC-related bleeding events than prophylactic platelet transfusion. (Funded by ZonMw; PACER Dutch Trial Register number, NL5534.).

Decitabine in Older Patients with AML: Quality of Life Results of the EORTC-GIMEMA-GMDS-SG Randomized Phase III Trial.

We hypothesized that fit older patients with acute myeloid leukemia (AML) treated with decitabine (DEC) would report better health-related quality of life (HRQoL) outcomes compared to those receiving intensive chemotherapy (IC). We conducted a phase 3 randomized trial to compare DEC (10-day schedule) to IC (3+7) in older fit AML patients. HRQoL was a secondary endpoint, and it was assessed with the EORTC QLQ-C30 and the QLQ-ELD14. The following scales were a priori selected for defining the primary endpoint: physical and role functioning, fatigue, pain, and burden of illness. HRQoL was assessed at baseline, at regeneration from cycle 2, and at 6 and 12 months after randomization, and also prior to allo-HSCT and 100 days after transplantation. Overall, 606 patients underwent randomization. At 2 months, the risk of HRQoL deterioration was lower in the DEC arm than in the 3+7 arm (76% [95% CI, 69 to 82] v 88% [95% CI, 82 to 93]; odds ratio, 0.43 [95% CI, 0.24 to 0.76], P=.003). No statistically significant HRQoL differences were observed between treatment arms at the long-term evaluation combining assessments at 6 and 12 months. HRQoL deteriorations between baseline and post-allo-HSCT were observed in both arms. However, these deteriorations were not clinically meaningful in patients randomized to DEC, while this was the case for those in the 3+7 arm, in four out of the five primary HRQoL scales. Our HRQoL findings suggest that lower-intensity treatment with DEC, may be preferable to current standard IC (3+7), in fit older AML patients. ClinicalTrials.gov (NCT02172872).

Clinical Impact of Polymerase Chain Reaction-Based Aspergillus and Azole Resistance Detection in Invasive Aspergillosis: A Prospective Multicenter Study.

BACKGROUND: Invasive aspergillosis (IA) by a triazole-resistant Aspergillus fumigatus is associated with high mortality. Real-time resistance detection will result in earlier initiation of appropriate therapy. METHODS: In a prospective study, we evaluated the clinical value of the AsperGenius polymerase chain reaction (PCR) assay in hematology patients from 12 centers. This PCR assay detects the most frequent cyp51A mutations in A. fumigatus conferring azole resistance. Patients were included when a computed tomography scan showed a pulmonary infiltrate and bronchoalveolar fluid (BALf) sampling was performed. The primary end point was antifungal treatment failure in patients with azole-resistant IA. RESULTS: Of 323 patients enrolled, complete mycological and radiological information was available for 276 (94%), and probable IA was diagnosed in 99/276 (36%). Sufficient BALf for PCR testing was available for 293/323 (91%). Aspergillus DNA was detected in 116/293 (40%) and A. fumigatus DNA in 89/293 (30%). The resistance PCR was conclusive in 58/89 (65%) and resistance detected in 8/58 (14%). Two had a mixed azole-susceptible/azole-resistant infection. In the 6 remaining patients, treatment failure was observed in 1. Galactomannan positivity was associated with mortality (P = .004) while an isolated positive Aspergillus PCR was not (P = .83). CONCLUSIONS: Real-time PCR-based resistance testing may help to limit the clinical impact of triazole resistance. In contrast, the clinical impact of an isolated positive Aspergillus PCR on BALf seems limited. The interpretation of the EORTC/MSGERC PCR criterion for BALf may need further specification (eg, minimum cycle threshold value and/or PCR positive on >1 BALf sample).

Voriconazole Resistance and Mortality in Invasive Aspergillosis: A Multicenter Retrospective Cohort Study.

BACKGROUND: Triazole resistance is an increasing problem in invasive aspergillosis (IA). Small case series show mortality rates of 50%-100% in patients infected with a triazole-resistant Aspergillus fumigatus, but a direct comparison with triazole-susceptible IA is lacking. METHODS: A 5-year retrospective cohort study (2011-2015) was conducted to compare mortality in patients with voriconazole-susceptible and voriconazole-resistant IA. Aspergillus fumigatus culture-positive patients were investigated to identify patients with proven, probable, and putative IA. Clinical characteristics, day 42 and day 90 mortality, triazole-resistance profiles, and antifungal treatments were investigated. RESULTS: Of 196 patients with IA, 37 (19%) harbored a voriconazole-resistant infection. Hematological malignancy was the underlying disease in 103 (53%) patients, and 154 (79%) patients were started on voriconazole. Compared with voriconazole-susceptible cases, voriconazole resistance was associated with an increase in overall mortality of 21% on day 42 (49% vs 28%; P = .017) and 25% on day 90 (62% vs 37%; P = .0038). In non-intensive care unit patients, a 19% lower survival rate was observed in voriconazole-resistant cases at day 42 (P = .045). The mortality in patients who received appropriate initial voriconazole therapy was 24% compared with 47% in those who received inappropriate therapy (P = .016), despite switching to appropriate antifungal therapy after a median of 10 days. CONCLUSIONS: Voriconazole resistance was associated with an excess overall mortality of 21% at day 42 and 25% at day 90 in patients with IA. A delay in the initiation of appropriate antifungal therapy was associated with increased overall mortality.

Phase I/II Trial of a Combination of Anti-CD3/CD7 Immunotoxins for Steroid-Refractory Acute Graft-versus-Host Disease.

Effective therapies for treating patients with steroid-refractory acute graft-versus-host-disease (SR-aGVHD), particularly strategies that reduce the duration of immunosuppression following remission, are urgently needed. The investigated immunotoxin combination consists of a mixture of anti-CD3 and anti-CD7 antibodies separately conjugated to recombinant ricin A (CD3/CD7-IT), which induces in vivo depletion of T cells and natural killer (NK) cells and suppresses T cell receptor activation. We conducted a phase I/II trial to examine the safety and efficacy of CD3/CD7-IT in 20 patients with SR-aGVHD; 17 of these patients (85%) had severe SR-aGVHD, and all 20 patients had visceral organ involvement, including 18 (90%) with gastrointestinal (GI) involvement and 5 (25%) with liver involvement. A validated 2-biomarker algorithm classified the majority of patients (11 of 20) as high risk. On day 28 after the start of CD3/CD7-IT therapy, the overall response rate was 60% (12 of 20), with 10 patients (50%) achieving a complete response. The 6-month overall survival rate was 60% (12 of 20), including 64% (7 of 11) classified as high risk by biomarkers. The 1-week course of treatment with CD3/CD7-IT caused profound but transient depletion of T cells and NK cells, followed by rapid recovery of the immune system with a diverse TCR Vß repertoire, and preservation of Epstein-Barr virus- and cytomegalovirus-specific T cell clones. Furthermore, our results indicate that CD3/CD7-IT appeared to be safe and well tolerated, with a relatively low prevalence of manageable and reversible adverse events, primarily worsening of hypoalbuminemia, microangiopathy, and thrombocytopenia. These encouraging results suggest that CD3/CD7-IT may improve patient outcomes in patients with SR-aGVHD.

Targeting the interleukin-1 pathway in patients with hematological disorders.

Interleukin-1α (IL-1α) and IL-1ß are potent inflammatory cytokines that activate local and systemic inflammatory processes and are involved in protective immune responses against infections. However, their dysregulated production and signaling can aggravate tissue damage during infection, inflammatory diseases, and chemotherapy-induced intestinal mucositis. Additionally, cytokines of the IL-1 family play an important role in homeostatic as well as "emergency" hematopoiesis and are involved in the pathogenesis of several myeloid and lymphoid hematological malignancies. In the pathogenesis of intestinal mucositis and graft-versus-host disease (GVHD), these cytokines are considered pivotal during the initiation as well as propagation phase, and insights from animal studies suggest that targeting the IL-1 pathway can significantly ameliorate mucositis and GVHD. Moreover, IL-1α and IL-1ß might prove to be valuable targets for both prevention and treatment of cancer and cancer therapy-related complications, and the first clinical studies have already been performed in the setting of hematological malignancies. In this review, we will discuss the role of cytokines of the IL-1 family in hematological malignancies, chemotherapy-induced intestinal mucositis, and GVHD, and speculate on possibilities of therapeutically targeting the IL-1 pathway in hematological patients.

Moderate correlation between systemic IL-6 responses and CRP with trough concentrations of voriconazole.

AIMS: Voriconazole (VCZ) exhibits wide intrapatient pharmacokinetic variability, which is disadvantageous because of its narrow therapeutic range. A considerable part of this variation remains unexplainable, despite extensive knowledge of this drug. It is hypothesized that inflammation has an impact on VCZ pharmacokinetics. In the present study, we investigated the correlation between VCZ trough concentrations and various cytokines. METHODS: A prospective single-centre analysis was performed in adult haematology patients receiving VCZ for possible, probable or proven invasive fungal disease. A linear mixed model was built to explore the contribution of each of the seven pro- and anti-inflammatory cytokines to VCZ trough levels. The Akaike information criterion (AIC) was used to determine the model that fitted the best. RESULTS: Twenty-two patients, with a total of 143 combined samples of VCZ trough levels and cytokines, were included. A significant correlation (P < 0.005) was found between VCZ trough concentrations and interleukin (IL) 6, IL-8 and C-reactive protein (CRP). IL-6 showed the lowest AIC, although differences with the other mediators were marginal. CONCLUSION: VCZ trough concentrations correlate with IL-6, IL-8 and CRP levels but only moderately explain the variability in VCZ pharmacokinetics. Future prospective studies should be undertaken to confirm these findings, and incorporate the data obtained into pharmacokinetic models, to refine the predictive behaviour.

The diagnosis and treatment of invasive aspergillosis in Dutch haematology units facing a rapidly increasing prevalence of azole-resistance. A nationwide survey and rationale for the DB-MSG 002 study protocol.

Patients with haematological malignancies are at risk for invasive fungal diseases (IFD). A survey was conducted in all Dutch academic haematology centres on their current diagnostic, prophylactic and therapeutic approach towards IFD in the context of azole-resistance. In all 8 centres, a haematologist and microbiologist filled in the questionnaire that focused on different subgroups of haematology patients. Fungal prophylaxis during neutropaenia was directed against Candida and consisted of fluconazole and/or amphotericin B suspension. Mould-active prophylaxis was given to acute myeloid leukaemia patients during chemotherapy in 2 of 8 centres. All centres used azole prophylaxis in a subset of patients with graft-versus-host disease. A uniform approach towards the diagnosis and treatment of IFD and in particular azole-resistant Aspergillus fumigatus was lacking. In 2017, all centres agreed to implement a uniform diagnostic and treatment algorithm regarding invasive aspergillosis with a central role for comprehensive diagnostics and PCR-based detection of azole-resistance. This study (DB-MSG 002) will re-evaluate this algorithm when 280 patients have been treated. A heterogeneous approach towards antifungal prophylaxis, diagnosis and treatment was apparent in the Netherlands. Facing triazole-resistance, consensus was reached on the implementation of a uniform diagnostic approach in all 8 centres.

Recurrent mutations in genes involved in nuclear factor-κB signalling in nodal marginal zone lymphoma-diagnostic and therapeutic implications.

AIMS: To investigate the spectrum of mutations in 20 genes involved in B-cell receptor and/or Toll-like receptor signalling resulting in activation of nuclear factor-κB (NF-κB) in 20 nodal marginal zone lymphomas (NMZLs), 20 follicular lymphomas (FLs), and 11 cases of B-cell lymphoma, unclassifiable (BCL-u). METHODS AND RESULTS: Nodal marginal zone lymphomas were diagnosed according to strict criteria, including the expression of at least one putative marginal zone marker (MNDA and/or IRTA1). Cases that showed features of NMZL but did not fulfil all criteria were included as BCL-u. All FLs were required to have a BCL2 rearrangement. Mutations were found in: nine NMZLs, with recurrent mutations in TNFAIP3 and CD79B; 12 FLs, with recurrent mutations in TNFRSF14, TNFAIP3, and CARD11; and five cases of BCL-u, with recurrent mutations in TNFRSF14. TNFRSF14 mutations were present in FL and BCL-u, but not in any of the NMZLs. In the BCL-u group, TNFRSF14 mutations clustered with a FL immunophenotype. CONCLUSIONS: These results suggest that TNFRSF14 mutations point towards a diagnosis of FL, and can be used in the sometimes difficult distinction between NMZL and FL, but to apply this in diagnostics would require confirmation in an independent cohort. In addition, the presence or absence of specific mutations in pathways converging on NF-κB could be important for decisions regarding targeted treatment.

Combination Therapy with Inolimomab and Etanercept for Severe Steroid-Refractory Acute Graft-versus-Host Disease.

Steroid-refractory acute graft-versus-host disease (aGVHD) remains an important cause of morbidity and mortality after allogeneic stem cell transplantation (SCT). A protocol on the management of aGVHD was introduced in our center that incorporated a prospective study on combination therapy with inolimomab (anti-IL-2Rα) and etanercept (anti-tumor necrosis factor-α) for steroid-refractory aGVHD. We evaluated the efficacy and safety in 21 consecutively treated patients. The patients had developed refractory aGVHD after SCT (n = 16) or donor lymphocyte infusion (n = 5), and aGVHD was classified as severe in all patients, mostly due to gastrointestinal involvement stages 2 to 4. No drug-related side effects were observed apart from the infections expected to occur in these severely immunocompromised patients. Overall response at day 28 of second-line therapy was 48% (10/21), with 6 and 4 patients achieving a complete and partial response, respectively. Eventually, 19 patients died (90%), with early mortality (<6 months) predominantly resulting from refractory aGVHD and secondary infections and late mortality resulting from relapse of the underlying disease. With a median follow-up of 55 days, the estimated rates of 6-month and 2-year overall survival were dismal, 29% and 10%, respectively. In conclusion, the combination of inolimomab and etanercept for steroid-refractory aGVHD failed to improve the dismal prognosis of severe steroid-refractory aGVHD.

Addition of 10-Day Decitabine to Fludarabine/Total Body Irradiation Conditioning is Feasible and Induces Tumor-Associated Antigen-Specific T Cell Responses.

Allogeneic hematopoietic cell transplantation (HCT) offers the possibility of curative therapy for patients with myelodysplastic syndromes (MDS), chronic myelomonocytic leukemia (CMML), and acute myelogenous leukemia (AML). However, post-HCT relapse remains a major problem, particularly in patients with high-risk cytogenetics and in patients who cannot tolerate consolidation chemotherapy (eg, due to previous toxicity). We assessed the toxicity and efficacy of 10-day decitabine (Dec), fludarabine (Flu), and 2 Gy total body irradiation (TBI) as a new conditioning regimen for allogeneic HCT in patients with MDS, CMML, or AML. Thirty patients were enrolled, including 11 with MDS, 2 with CMML, and 17 with AML. Patients received 20 mg/m(2)/day Dec on days -11 to -2, 30 mg/m(2)/day Flu on days -4 to -2, and 2 Gy TBI on day -1, followed by infusion of a donor stem cell graft on day 0. Postgrafting immunosuppression consisted of cyclosporin A and mycophenolate mofetil. At a median follow-up of 443 days, the overall survival was 53%, relapse incidence was 27%, and nonrelapse mortality was 27%. The incidence of severe acute (grade III/IV) graft-versus-host disease (GVHD) was 27%, and that of (predominantly mild) chronic GVHD was 60%. Immunomonitoring studies revealed that specific CD8(+) T cell responses against epigenetically silenced tumor-associated antigens (TAAs), including cancer-testis antigens (MAGE-A1/A2/A3 and PRAME) and RHAMM, occurred more frequently in patients who had received Dec/Flu/TBI conditioning (8 of 11 patients) compared with a control group of patients who had received only Flu/TBI conditioning (2 of 9 patients). In summary, Dec/Flu/TBI conditioning proved feasible and effective and enhanced the induction of TAA-reactive CD8(+) T cell responses in vivo, which may contribute to disease control post-transplantation.

'Trained immunity': consequences for lymphoid malignancies.

In hematological malignancies complex interactions exist between the immune system, microorganisms and malignant cells. On one hand, microorganisms can induce cancer, as illustrated by specific infection-induced lymphoproliferative diseases such as Helicobacter pylori-associated gastric mucosa-associated lymphoid tissue lymphoma. On the other hand, malignant cells create an immunosuppressive environment for their own benefit, but this also results in an increased risk of infections. Disrupted innate immunity contributes to the neoplastic transformation of blood cells by several mechanisms, including the uncontrolled clearance of microbial and autoantigens resulting in chronic immune stimulation and proliferation, chronic inflammation, and defective immune surveillance and anti-cancer immunity. Restoring dysfunction or enhancing responsiveness of the innate immune system might therefore represent a new angle for the prevention and treatment of hematological malignancies, in particular lymphoid malignancies and associated infections. Recently, it has been shown that cells of the innate immune system, such as monocytes/macrophages and natural killer cells, harbor features of immunological memory and display enhanced functionality long-term after stimulation with certain microorganisms and vaccines. These functional changes rely on epigenetic reprogramming and have been termed 'trained immunity'. In this review the concept of 'trained immunity' is discussed in the setting of lymphoid malignancies. Amelioration of infectious complications and hematological disease progression can be envisioned to result from the induction of trained immunity, but future studies are required to prove this exciting new hypothesis.

Atypical presentation of 'acalculous cholecystitis' with marked isolated hyperbilirubinaemia in patients treated for haematological malignancies.

Four patients diagnosed with haematological malignancies developed an isolated hyperbilirubinaemia following cytarabine- and anthracycline-based chemotherapy. The clinical picture was consistent with acalculous cholecystitis, but ultrasonography did not show the typical gallbladder wall thickening. All patients suffered from severe mucositis with neutropenic enterocolitis. We hypothesise that damage of the mucosa of the gallbladder induced by chemotherapy results in hyperpermeability of the mucosal barrier with bile leakage and isolated hyperbilirubinaemia.

Targeting the IL17 pathway for the prevention of graft-versus-host disease.

Graft-versus-host disease (GVHD) is still a major complication of allogeneic stem cell transplantation (allo-SCT). The pathophysiology of GVHD is a multistep process initiated by tissue damage and proinflammatory cytokine cascades induced by the pretransplantation conditioning therapy. This eventually results in Th1-driven tissue damage. However, increasing evidence indicates the involvement of IL17-producing T cells in GVHD pathogenesis. Both CD4(+) and CD8(+) IL17-producing T cells are suspected of initiating the Th1 response and aggravating tissue inflammation, resulting in full-blown GVHD. In this review, we discuss the involvement of IL17-producing T cells in GVHD and the factors involved in their expansion, differentiation, and activation. Different dendritic cell (DC) subsets, such as plasmacytoid DCs and DC NK lectin group receptor 1(+) myeloid DCs have the capability to stimulate Th/Tc17 responses through the release of cytokines. Pivotal cytokines include IL1ß, IL6, IL23, and TGFß, which are known to drive differentiation and expansion of IL17-producing T cells, and these cytokines are highly elevated in patients after allo-SCT. Potent activators of these DC subsets are motifs that are released upon tissue damage and microbial exposure during allo-SCT. These motifs aggravate the Th/Tc17 response via the activation of various pathogen recognition receptors, thereby initiating and perpetuating GVHD. A more comprehensive understanding of the factors and DC subsets driving the IL17 pathway will result in developing and testing novel therapeutic approaches for the prevention of GVHD.

Mucosal barrier injury, fever and infection in neutropenic patients with cancer: introducing the paradigm febrile mucositis.

Infection remains one of the most prominent complications after cytotoxic treatment for cancer. The connection between neutropenia and both infections and fever has long been designated as 'febrile neutropenia', but treatment with antimicrobial agents and haematopoietic growth factors has failed to significantly reduce its incidence. Moreover, emerging antimicrobial resistance is becoming a concern that necessitates the judicious use of available antimicrobial agents. In addition to neutropenia, patients who receive cytotoxic therapy experience mucosal barrier injury (MBI) or 'mucositis'. MBI creates a port-de-entrée for resident micro-organisms to cause blood stream infections and contributes directly to the occurrence of fever by disrupting the highly regulated host-microbe interactions, which, even in the absence of an infection, can result in strong inflammatory reactions. Indeed, MBI has been shown to be a pivotal factor in the occurrence of inflammatory complications after cytotoxic therapy. Hence, the concept 'febrile neutropenia' alone may no longer suffice and a new concept 'febrile mucositis' should be recognized as the two are at least complementary. This review we summarizes the existing evidence for both paradigms and proposes new therapeutic approaches to tackle the perturbed host-microbe interactions arising from cytotoxic therapy-induced tissue damage in order to reduce fever in neutropenic patients with cancer.

Host impairments in patients with neoplastic diseases.

Healthy individuals possess an immune system comprising physical barriers, innate and acquired immunity as well as the indigenous microflora that populate the body surfaces. The immune system maintains constant vigilance over the body at the cellular level as well as at the interface between the host integument and the resident microflora. However, neoplastic diseases and their treatment often lead to impaired immunity resulting in an increased risk of infections due to viruses, bacteria, fungi, and protozoa. This chapter explores the various aspects of host impairment focusing on the components of immunity and the interplay between them to explain why it is that these patients succumb to infections per se. In so doing, we hope that the reader will be better equipped to understand the risks patients face so as to anticipate potential infectious complications and implement appropriate measures to help attain successful remission of the neoplastic diseases and maintain the best quality of life for the patient.

Significant impact of antibiotic exposure on GI-GVHD, NRM, and GRFS following allogeneic HCT with non-myeloablative Flu-TBI conditioning.

BACKGROUND: Acute gastro-intestinal graft-versus-host disease (GI-GVHD) and non-relapse mortality (NRM) after allogeneic HCT are closely related to loss of microbial diversity and intestinal dominance by single taxa resulting from the use of antibiotics, dietary changes, and mucosal barrier injury. There is a paucity of data on the impact of use of antibiotics in HCT after Flu-TBI-based non-myeloablative (NMA) conditioning where there is absence of mucositis and limited malnutrition. METHODS: We did a retrospective single-center analysis of patients receiving Flu-TBI-based NMA HCT for a high-grade myeloid malignancy, mostly AML, and MDS, or acute lymphoblastic leukemia (ALL). We analyzed the impact of pre-engraftment antibiotic exposure, prophylactic ciprofloxacin, and or treatment with broad-spectrum cephalosporin/carbapenem, on HCT outcomes, with a focus on the incidence of acute GI-GVHD by day 180 and NRM at 1 year. RESULTS: A total of 150 patients were evaluable with a median age of 62 years. Antibiotics were used in 90 patients; 60 prophylactic use only and 30 therapeutic use with or without previous prophylaxis. Antibiotic use resulted in a significant higher incidence of GI-GVHD Stage 1-4; 29% (26/90) versus 5% (3/60) in those not receiving antibiotics (OR 8.1 (95% CI 2.3-28.3), p = 0.001). Use of antibiotics resulted in higher 1-year NRM (19% (17/90) versus 10% (6/60), HR 2.3, p = 0.06), and decreased 2-year GRFS (42% (38/90) versus 55% (33/60), HR 1.7, p = 0.04), but did not impact RFS or OS. CONCLUSIONS: Use of antibiotics was related to the occurrence of GI-GVHD, NRM, and GRFS in patients receiving truly NMA HCT. Therefore, in the absence of mucositis and low incidence of bacteremia, antibiotics can and should be used restrictively in this setting.